Build a prototype impl for a firmware distribution platform using ockam's secure channels

[sarath3192]

firmware distribution platform using Ockam secure channels.

sub-tasks

Using ockam secure channels -

• send and receive messages over a local network.
• send and receive messages over the internet.
• distribute firmware files over the internet.

[sarath3192]

Add support for Embassy executor for Ockam on Stm boards.